The invention relates to a scanning microscope with a beam deflector that directs an illumination light beam over or through a sample, and with a detector for receiving detection light exiting from the sample.
In scanning microscopy, a sample is illuminated with a light beam in order to observe the reflection or fluorescent light emitted by the sample. The focus of an illumination light beam is moved in an object plane with the help of a controllable beam deflector, generally by tipping two mirrors in an object plane, whereby the axes of deflection are usually positioned perpendicular to each other, so that one mirror deflects in the x-direction and the other in the y-direction. The mirrors are tipped with the help, for example, of galvanometric positioners. The power of the light coming from the object is measured dependent on the position of the scanning beam. Generally, the positioners are provided with sensors to determine the actual position of the mirrors.
In confocal scanning microscopy in particular, an object is scanned in three dimensions with the focus of a light beam.
A confocal scanning microscope generally comprises a light source, a focusing optic with which the light from the source is focused on a pinhole aperture—the so-called excitation aperture—, a beam splitter, a beam deflector to control the beam, a microscope optic, a detection aperture, and detectors to detect the detection or fluorescent light. The illumination light is coupled via a beam splitter. The fluorescent or reflection light coming from the object returns to the beam splitter via the beam deflector, passes through it, and finally focuses on the detection aperture, behind which are the detectors. Detection light that does not originate directly from the focal region takes another light path and does not pass through the detection aperture, so that pixel information is obtained that leads to a three-dimensional image as a result of sequential scanning of the object. In most cases, a three-dimensional image is achieved by layered data imaging, whereby the path of the scanning light beam ideally describes a meander pattern on or in the object (scanning a line in the x-direction at a constant y-position, then interrupting x-scanning and y-repositioning to the next line to be scanned, and then scanning this line at a constant y-position in negative x-direction, etc.). To enable layered data imaging, the sample table or the objective is repositioned after scanning a layer so that the next layer to be scanned is brought into the focal plane of the objective.
A microscope with a light source that emits light for illuminating a sample and with a spectrometer that receives the detection light exiting from the sample is known from DE 202 16 583 U1. The microscope has an optical arrangement with an acousto-optical component that directs the light from the light source to the sample, and directs the spectrally un-split detection light exiting from the sample to the spectrometer.